who found rubber in C. nauseoms, turbinatus, teretifolius, panicu- 

 latus, linifoliuH, with rubber rabbitbrush and its varieties the only 

 feasible source of commercial supply. Not even traces of rubber 

 were found in C. greenei, hoivardi, nevadensis, parryi, puberulus, and 

 humilis, C. viscidiflorus tortifolius. 



The occurrence of rubber in some rabbitbrushes has long been 

 known to the Indians, who masticated the wood and bark into a 

 crude chewing gum containing rubber. According to Professors 

 Hall and Goodspeed (op. tit.), Indians located near St. George, 

 Utah, as early as 1878, showed some Mormon boys how to make the 

 gum. The first samples of rabbitbrush rubber (called chrysil) for 

 scientific work were prepared by Piute Indians at Benton, Calif. 

 Although chrysil vulcanizes readily and yields a product superior to 

 most African or low-grade rubbers, it is inferior to the best grade 

 of Para rubber. The Navaho Indians used a decoction of the flowers 

 of various species of rabbitbrush for dyeing wool yellow 4 and Dr. 

 David P. Barrows reports that the Coahuilla Indians of southern 

 California used a tea made from C. graveolens (syn. C. nauseosux 

 graveolens) for coughs and pains in the chest. 8 



Most rabbitbrushes have narrow leaves and produce an abundance 

 of showy yellow flower clusters which often literally cover the bushes 

 during the autumn months. Because of these large masses of yellow 

 flowers a number of the species have been used locally for orna- 

 mental purposes and offer possibilities for wider cultivation. Tall 

 rabbitbrush (C. spetiosus, syn. C. pvlcherrimus) is especially hand- 

 some since it produces a greater abundance of golden yellow flowers 

 than any other native shrub within its range. 



As a rule, the flower heads are borne in clusters at the ends of the 

 stems, and each head contains from 5 to 30 perfect seed-producing 

 flowers surrounded by several rows of dry, papery or leathery over- 

 lapping bracts (involucre) whose tips are often herbaceous. The 

 branches of the seed-producing organ are appendaged and the 

 ripened "seed" (achene) is hairy or smooth, narrow, round or angu- 

 lar, with a crown of soft, white hairs 0.1 to 0.3 inch long. 



Many species of the western North American shrubby genus Chrysothamnus 

 were originally classified with the Old World cultivated goldilocks (lAnosyris 

 spp.) or with the South African genus Chrysocoma. In 1840 the eminent natu- 

 ralist, Thomas Nuttall, observed that the shrubs from the West were distinct 

 in aspect and characters from either of the two Old World genera mentioned. 

 This led him to establish his appropriately named genus Chrysothamnus. The 

 late Dr. Greene, a distinguished American taxonomist, who for the last 17 years 

 of his life was consulting plant identification expert for the United States 

 Forest Service, apparently was the first American botanist to recognize and use 

 Nuttall's name Chrysothamnus. The suppression of this name for 60 years 

 seems to have been due to the enormous prestige and influence of Dr. Asa 

 Gray, who preferred to place the Chrysothamni in the genus Bigelovia which 

 was established by the Swiss botanist DeCandolle. An examination of De 

 Candolle's original description of Bigelovia reveals that it was based on eastern 

 herbs, and that the name Bigelovia previously had been used for other genera 

 and accordingly is not tenable for this group. The use of Chrysothamnus as a 

 valid genus is now practically universal among botanists. 



3 See footnote on preceding page. 



4 Wooton, E. O., and Standley, P. C. FLORA OF NEW MEXICO. U. S. Natl. Mus., Contrib. 

 U. S. Natl. Herbarium 19, 794 pp. 1915. 



